Question

b) Give one example of polyatomic ion with valency 2 (write the formula of ion). ​

Answer 1

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Answer 2

The polyatomic ion which has a valency of 2 is the carbonate ion.

• The carbonate ion involves three oxygen atoms and one carbon atom and carries a complete charge of 2−.  

• The general formula of the carbonate ion is CO3- and carries an overall charge of 2.

• The atoms of a polyatomic ion are closely bonded together and therefore, the whole ion behaves as a single unit.

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